C / C++ / MFC

4-Feb-07 23:44

I've created a menu called Tools where in I have created a menu item called Preferences. If we click the Prefernces menu item Preferences Dialog Box will open. In that Dialog Box I have an edit box. The message entered in this edit box is displayed in the second panel of the status bar (i.e) panel no.1.

My Requirement is:
The second panel should be of a default size and it should grow according to the length of the message entered in the edit box.

How can I achieve this in MFC? Can any one help?

I have tried this also. But it didn't work.
CStatusBar::SetPaneInfo( int nIndex, UINT nID, UINT nStyle, int cxWidth );

The function that displays the message is:

void CPerspectiveDoc::OnShowMsg(CCmdUI* pCmdUI)
{
char str1[150];
//int len = message.GetLength();
sprintf(str1, "%s",message.GetString());
pCmdUI->Enable(TRUE);
pCmdUI->SetText((const char *)str1);
//m_wndStatusBar.SetPaneInfo(1, IDS_MESSAGE, SBPS_STRETCH, len);
}

When I remove the comment from the following code, it shows me an exception stating that "Unhandled exception at 0x7c1d71bb (MFC71.dll) in Perspective.exe: 0xC0000005: Access violation writing location 0x00000014."

The commented out line of code is:
//m_wndStatusBar.SetPaneInfo(1, IDS_MESSAGE, SBPS_STRETCH, len);

Any one Please help.

kasturi_haribabu5-Feb-07 0:04

kasturi_haribabu

5-Feb-07 0:04

I have tried with an and this code works.
May be something else is wrong...

CString message;
message = "A LOOOOOOOOOOOOOOOOOOOOONG MESSAGE000000";
int len = message.GetLength();
m_wndStatusBar.SetPaneText(1,(LPCTSTR)message,FALSE);
m_wndStatusBar.SetPaneInfo(1, 1, SBPS_STRETCH, len);

T.RATHA KRISHNAN5-Feb-07 0:20

5-Feb-07 0:20

The method that displays message is:

The function that displays the message is:

void CPerspectiveDoc::OnShowMsg(CCmdUI* pCmdUI)
{
char str1[150];
//int len = message.GetLength();
sprintf(str1, "%s",message.GetString());
pCmdUI->Enable(TRUE);
pCmdUI->SetText((const char *)str1);
//m_wndStatusBar.SetPaneInfo(1, IDS_MESSAGE, SBPS_STRETCH, len);
}

I can't use SetPaneText and SetPaneInfo with this CCmdUI* (pCmdUI) object pointer. If I comment out this: //m_wndStatusBar.SetPaneInfo(1, IDS_MESSAGE, SBPS_STRETCH, len);I got an exeption.

More over we should not initialize the string "message" in the code. We should get it through GetString method for edit box. The status bar pane should grow according to the length of the string.

static UINT indicators[] =
{
0,// ID_SEPARATOR
IDS_MESSAGE,
ID_SHOWFPS,
};

This method is in some other source file. Is this a reason for this error?

#realJSOP5-Feb-07 0:07

5-Feb-07 0:07

1) There are several status bar articles on CP. Check one of them to see if they have the info you need. I used one that makes it a bit simpler to add custom panes and update them when necessary. In fact, there's one article here that allows better control over the status bar than the default MFC class allows. Try here: http://www.codeproject.com/statusbar/ExtStatusControlBar.asp[^]

2) This comment is based on a complete lack of knowledge where your requirements are concerned - It seems to me that you're approaching this incorrectly. If it were me I'd be setting the status bar pane text when the dialog box exists with IDOK. Handling it in a command update function is beyond funky. If you set the text in the dialog box, there's no reason for it to change in the status bar until you change it in the dialog box again.

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

#realJSOP5-Feb-07 0:29

MFC STATUS BAR PROBLEM ADDITIONAL

5-Feb-07 0:29

By the way, I think you're going to have to calculate the new size manually and then pass that value into the status bar.

T.RATHA KRISHNAN5-Feb-07 1:10

Re: MFC STATUS BAR PROBLEM ADDITIONAL

5-Feb-07 1:10

Not only manually, the status bar pane should grow dynamically i.e as and when I enter one character in to the edit box the status bar pane should grow one character length. This way the status pane will have to grow for hundred characters length that is entered via the edit box.How can I do?

#realJSOP5-Feb-07 1:40

Re: MFC STATUS BAR PROBLEM ADDITIONAL [modified]

5-Feb-07 1:40

Well, I wouldn't change the statusbar until AFTER the user clicks OK, but that's just me. However...

1) In your dialog box, you would have to handle the EN_CHANGE message for the edit control. Every time the user types a character you have to calculate the new width of the string in pixels.

2) I would send a message to the parent view that contained a pointer to the string, and let the parent view do the width calculations. This message would probably be one you have to define (WM_APP+n) and manually add a handler for in your view.

3) When the view gets the message, it gets the string from the passed-in pointer value and creates a CPaintDC object. This dc object can then provide the width of the string via the GetTextExtent() function. This new width would be passed to the status bar for the appropriate pane, and the text would be applied to that pane.

If you decide to handle the status bar update after the user clicks the OK button in your dialog box, you can skip steps 1 and 2, and just retrieve the string from the dialog box itself, and do step 3.

I assume you're a programmer (and you obviously have access to the internet, so you can look stuff up on your own), so I leave it to you to work out the specifics.

T.RATHA KRISHNAN5-Feb-07 17:40

Re: MFC STATUS BAR PROBLEM ADDITIONAL

5-Feb-07 17:40

When I add the EN_CHANGE message the following error occurs.

error C2440: cannot convert from CSize to int

error C2440:'static_cast':cannot covert from 'int(__thiscall CPreferences::*)(void)' to 'AFX_PMSG'

the code I added was,

int CPreferences::OnEnChangeEditmessage()
{
CPaintDC *pDC;
int size;
size = pDC->GetTextExtent(m_strMessage);
return size;
}

The message map I added was,
ON_EN_CHANGE(IDC_EDITMESSAGE, OnEnChangeEditmessage)

The afx message I added was,
afx_msg int OnEnChangeEditmessage();

What to do?

-- modified at 4:00 Tuesday 6th February, 2007

#realJSOP5-Feb-07 23:13

Re: MFC STATUS BAR PROBLEM ADDITIONAL [modified]

5-Feb-07 23:13

Did you look on MSDN for documentation on GetTextExtent()? It returns a CSize structure, NOT an int.

T.RATHA KRISHNAN6-Feb-07 1:42

Please help, SendMesssage not working in MFC Dialog Application, (with wizard)

6-Feb-07 1:42

Ya! It's true. When I use the following code,

void CPerspectiveDoc::OnShowMsg(CCmdUI* pCmdUI)
{
//char str1[150];
CString strValue;
strValue.Format("%s", message.GetString());
//strValue.SetLength(100);

//sprintf(str1, "%s",message.GetString());
pCmdUI->Enable(TRUE);
pCmdUI->SetText(strValue);
CDC* pDC = m_wndStatusBar.GetDC();

CSize mSize = pDC->GetTextExtent(strValue);
m_wndStatusBar.SetPaneInfo(1, IDS_MESSAGE, SBPS_NORMAL, mSize.cx);
//m_wndStatusBar.SetPaneInfo(1, IDS_MESSAGE, SBPS_STRETCH, len);
}
I got the following exception.

'Unhandled exception at 0x7c1d71bb (MFC71.dll) in Perspective.exe: 0xC0000005: Access violation writing location 0x00000014.'

If I break this exception, it ends in a class barstat.cpp

If I comment out this line,

m_wndStatusBar.SetPaneInfo(1, IDS_MESSAGE, SBPS_NORMAL, mSize.cx);
exception didn't arise.

I have declared m_wndStatusBar variable in some other class.
How do I make this variable visible to this class CPerspectiveDoc.
-- modified at 23:42 Tuesday 6th February, 2007

XTr1NiTy4-Feb-07 23:17

Re: Please help, SendMesssage not working in MFC Dialog Application, (with wizard)

4-Feb-07 23:17

Greetings all,

Im trying to send messages to a main dialog, but it seems that the messages does not get received.

extern CListBox* hList;<br />
.<br />
.<br />
.<br />
if (lTotalCols > 0)<br />
	{<br />
<br />
		//SendMessage(LVM_DELETEALLITEMS, 0,0);<br />
		// Clear all the previous listview item<br />
		SendMessage((HWND)hList, LVM_DELETEALLITEMS, 0, 0);<br />
		// Clear the previous column header<br />
		for (idx=0; idx<lTotalCols; idx++)<br />
		{<br />
			SendMessage((HWND)hList, LVM_DELETECOLUMN, (int)0, 0);<br />
			//SendMessage(hList, LVM_DELETECOLUMN, (int)0, 0);<br />
		};<br />
	}<br />

Any Suggestions of what to try?

Reinart Laast,
Junior Developer.
Greetings from South Africa

kasturi_haribabu4-Feb-07 23:44

kasturi_haribabu

4-Feb-07 23:44

extern CListBox* hList;

SendMessage((HWND)hList, LVM_DELETEALLITEMS, 0, 0);

(HWND)hList is pointing to a CListBox handle. that means, Message is being sent to the List box.
is that what you intend to do?

Pass the handle of the MainDialog here.. Smile | :)

regards,
Haribabu

Re: Please help, SendMesssage not working in MFC Dialog Application, (with wizard)

#realJSOP4-Feb-07 23:47

Re: Please help, SendMesssage not working in MFC Dialog Application, (with wizard)

4-Feb-07 23:47

Keep in mind that I haven't tried this or looked around on MSDN/web (like you could easily do yourself), so I don't know if this is going to work, but try one of these:

SendMessage(WM_COMMAND, LVM_DELETEALLITEMS, 0);
SendMessage(WM_MESSAGE, LVM_DELETEALLITEMS, 0);

XTr1NiTy5-Feb-07 0:16

Re: Please help, SendMesssage not working in MFC Dialog Application, (with wizard) [modified]

5-Feb-07 0:16

Thank you, I'll try to find out if i could get it working in that way as well.

XTr1NiTy5-Feb-07 0:02

Re: Please help, SendMesssage not working in MFC Dialog Application, (with wizard)

5-Feb-07 0:02

Thanks Haribabu, and that is the intention actually, sorry if i phrased the question wrong D'Oh! | :doh:

I want to clear the listbox and insert the items from the function im sending the messages from, the listbox is on the main dialog, but when i add an messagebox that should receive LVM_DELETEALLITEMS message, it doesnt work.
As if the messages go somewhere else or nowhere at all.

BOOL frmMenu::OnInitDialog() <br />
{<br />
	CDialog::OnInitDialog();<br />
	this->SetRedraw(true);<br />
	<br />
	// TODO: Add extra initialization here<br />
	hList = (CListBox*)(GetDlgItem(IDC_LIST));<br />
	<br />
	return TRUE;  // return TRUE unless you set the focus to a control<br />
	              // EXCEPTION: OCX Property Pages should return FALSE<br />
}

void frmMenu::OnDeleteallitemsList(NMHDR* pNMHDR, LRESULT* pResult) <br />
{<br />
	NM_LISTVIEW* pNMListView = (NM_LISTVIEW*)pNMHDR;<br />
	// TODO: Add your control notification handler code here<br />
	<br />
//Supposed to show when message was received as a test.<br />
AfxMessageBox(TEXT("Got it"));<br />
	<br />
	*pResult = 0;<br />
}

-- modified at 6:10 Monday 5th February, 2007

#realJSOP5-Feb-07 0:24

Re: Please help, SendMesssage not working in MFC Dialog Application, (with wizard)

5-Feb-07 0:24

1) Add a control variable for the listctrl. It will simplify further manipulation of the control, eliminating the need for code like this:

hList = (CListBox*)(GetDlgItem(IDC_LIST));

2) If you want to remove all items from the list control, use this (based on your apparent current code):

hList->DeleteAllItems();

3) There's no need to send a message to the listbox (see item #2 above).

4) Quite frankly, your naming conventions suck. Personally, I would never name a dialog box class something like "frmMenu". If you scan file names and you see frmmenu.cpp, wouldn't you assume that file contains some sort of menu code?

Is the message you're sending coming from outside the dialog box? If so, make a programmer-defined message and handle it that way:

// in a separate header file, like "CustomMessages.h"

#define UWM_DELETE_ALL_ITEMS WM_APP+1

// in the dlg header file
#include "CustomeMessages.h"
class frmMenu public
{
public:
afx_msg LRESULT OnDeleteAllItems(WPARAM wParam=0, LPARAM lParam=0);
};

// in the dlg cpp file
{MESSAGE_MAP
   ON_MESSAGE(UWM_DELETE_ALL_ITEMS, OnDeleteAllItems)
MESSAGE_MAP}

LRESULT frmMenu::OnDeleteAllItems(WPARAM wParam, LPARAM lParam)
{
    lParam;
    wParam;
    ((CListBox*)(GetDlgItem(IDC_LIST)))->DeleteAllItems();
    return 1L;
}

This was all done off the top of my head, so you may need to adjust the code to fit/compile, but this should do what you need.

XTr1NiTy5-Feb-07 0:43

Re: Please help, SendMesssage not working in MFC Dialog Application, (with wizard)

5-Feb-07 0:43

Thanks, this will work with EVC++ 4.0? Because im doing this for a win ce device. I already have a control variable for the control, should i rather use that?

And the naming convention thing i know, that was a slip from the c# i've done for menu forms.
Only recently started dabbling in c++ Confused | :confused:

#realJSOP5-Feb-07 1:47

Re: Please help, SendMesssage not working in MFC Dialog Application, (with wizard)

5-Feb-07 1:47

I have no clue if it will work in that environment, but there is little in MFC that doesn't (MSDN sometimes points out CE-specific concerns). My advice is to give it a try. We also have a Windows CE forum here that yo could post CE-specific questions in.

I have some more advice for you. When you ask questions here, provide as much detail on your requirements as you can. It's hard enough to answer ambiguous questions, and not knowing the requirements make sit harder to give you the right answer the first time. For this particular thread, you should have started out with something like this:

Compiler: EVC 4.0
Framework: Windows CE application using MFC
Experience: I'm new at this C++ stuff, so go kinda slow.

And then proceed with a DETAILED description of your problem, and what you've tried to fix it. This will keep us from having to go over stuff you've trie or point you to where you went wrong.

XTr1NiTy5-Feb-07 1:19

Re: Please help, SendMesssage not working in MFC Dialog Application, (with wizard)

5-Feb-07 1:19

All my messages come from outside the dlg class, so should i rather define all the messages in a custom message .cpp file?

Not only for delete as well as the populating of the listbox, because at the moment i try to fill it with messages as well with -

<br />
// Display the rows.<br />
    while(lNumRowsRetrieved > 0)<br />
	{<br />
        //For each row, print the column data.<br />
        for(lCount=0; lCount<lNumRowsRetrieved; lCount++)<br />
		{<br />
			// Initialize...<br />
            memset(pBuffer, 0, ConsumerBufColOffset);<br />
            // Get the row data values.<br />
			pIRowset->GetData(hRows[lCount], hAccessor, pBuffer);<br />
			<br />
			// -- Item<br />
			pitem.mask = LVIF_TEXT;<br />
			pitem.iItem = SendMessage((HWND)hList, LVM_GETITEMCOUNT, 0, 0);<br />
			//pitem.iItem = SendMessage(hList, LVM_GETITEMCOUNT, 0, 0);<br />
			pitem.pszText = (LPTSTR)&pBuffer[pBindings[0].obValue];<br />
			pitem.iSubItem = 0;<br />
			// Insert item<br />
			idx = SendMessage((HWND)hList, LVM_INSERTITEM, 0, (LPARAM)&pitem);<br />
			//idx = SendMessage(hList, LVM_INSERTITEM, 0, (LPARAM)&pitem);<br />
<br />
			// Walk through each columns...<br />
			for (lColumn=1; lColumn<lNumCols; lColumn++)<br />
			{<br />
				pitem.mask = LVIF_TEXT;<br />
				pitem.iItem = idx;<br />
				pitem.pszText = (LPTSTR)&pBuffer[pBindings[lColumn].obValue];<br />
				pitem.iSubItem = lColumn;<br />
				// Insert subitem<br />
				SendMessage((HWND)hList, LVM_SETITEM, 0, (LPARAM)&pitem);		<br />
				//SendMessage(hList, LVM_SETITEM, 0, (LPARAM)&pitem);		<br />
			}<br />
<br />
			// Update the total column counter by 1<br />
			lTotalRows++;<br />
        };

#realJSOP5-Feb-07 1:50

Re: Please help, SendMesssage not working in MFC Dialog Application, (with wizard)

5-Feb-07 1:50

I think you're going to have to describe what your app is doing and why you're handling it the way you are.

XTr1NiTy5-Feb-07 2:06

Re: Please help, SendMesssage not working in MFC Dialog Application, (with wizard)

5-Feb-07 2:06

Oh Ok, what im trying to achieve is to insert items from a function separate from the dlg code, which retrieves rows from a database to display the last 5 or so inserted records that you can refresh with a click or timer, on a small menu dialog that should stay on the mobile device screen.
But the dialog im trying to send the messages to doesnt seem te receive the messages, like the message pump doesnt get the messages to send. The above code is to insert the items to the listbox with messagea, im also working from examples as i dont have a lot of c++ exp. So a lot of the code is from the examples. Any advice is very welcome.

#realJSOP5-Feb-07 2:25

Re: Please help, SendMesssage not working in MFC Dialog Application, (with wizard)

5-Feb-07 2:25

Why don't you access the database from within the dialog box? You can create a worker thread that runs the timer, and another worker thread that actually accesses the database and that sends a message back to the dialog that tells the dialog to refresh the list.

In fact, the app should be a dialog based app if that's all it does.

I wrote a series of articles that includes a part that describes a similar process.

http://www.codeproject.com/samples/SDIMultiSplit_Part3.asp[^]

The threading stuff is about halfway down the page, and the classes I included in the demo source code should be easily modifiable to fit your needs. Nothing is free, so be prepared to try to figure this stuff out on your own (because only YOU know all of your requirements). You'll learn more that way. I can say that the timer thread should be a direct drop-in in your code. You also don't have to worry about the status bar panes, so passing a NULL in for the timer thread for that parameter should be fine.

Have a ball.

XTr1NiTy5-Feb-07 2:47